Kernel: Implement RamdiskDevice

Author: https://github.com/boricj
Commit: https://github.com/SerenityOS/serenity/commit/225957283ef
Pull-request: https://github.com/SerenityOS/serenity/pull/5028
Reviewed-by: https://github.com/awesomekling

Kernel/CMakeLists.txt

@@ -46,6 +46,8 @@ set(KERNEL_SOURCES
     Storage/IDEController.cpp
     Storage/IDEChannel.cpp
     Storage/PATADiskDevice.cpp
+    Storage/RamdiskController.cpp
+    Storage/RamdiskDevice.cpp
     Storage/StorageManagement.cpp
     DoubleBuffer.cpp
     FileSystem/AnonymousFile.cpp

Kernel/Storage/RamdiskController.cpp

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/OwnPtr.h>
+#include <AK/RefPtr.h>
+#include <AK/Types.h>
+#include <Kernel/Storage/RamdiskController.h>
+
+namespace Kernel {
+
+NonnullRefPtr<RamdiskController> RamdiskController::initialize()
+{
+    return adopt(*new RamdiskController());
+}
+
+bool RamdiskController::reset()
+{
+    TODO();
+}
+
+bool RamdiskController::shutdown()
+{
+    TODO();
+}
+
+size_t RamdiskController::devices_count() const
+{
+    return m_devices.size();
+}
+
+void RamdiskController::start_request(const StorageDevice&, AsyncBlockDeviceRequest&)
+{
+    ASSERT_NOT_REACHED();
+}
+
+void RamdiskController::complete_current_request(AsyncDeviceRequest::RequestResult)
+{
+    ASSERT_NOT_REACHED();
+}
+
+RamdiskController::RamdiskController()
+    : StorageController()
+{
+    // Populate ramdisk controllers from Multiboot boot modules, if any.
+    size_t count = 0;
+    for (auto used_memory_range : MemoryManager::the().used_memory_ranges()) {
+        if (used_memory_range.type == UsedMemoryRangeType::BootModule) {
+            size_t length = PAGE_ROUND_UP(used_memory_range.end.get()) - used_memory_range.start.get();
+            auto region = MemoryManager::the().allocate_kernel_region(used_memory_range.start, length, "Ramdisk", Region::Access::Read | Region::Access::Write);
+            m_devices.append(RamdiskDevice::create(*this, move(region), 6, count));
+            count++;
+        }
+    }
+}
+
+RamdiskController::~RamdiskController()
+{
+}
+
+RefPtr<StorageDevice> RamdiskController::device(u32 index) const
+{
+    if (index >= m_devices.size())
+        return nullptr;
+    return m_devices[index];
+}
+
+}

Kernel/Storage/RamdiskController.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/OwnPtr.h>
+#include <AK/RefPtr.h>
+#include <AK/Types.h>
+#include <Kernel/Storage/RamdiskDevice.h>
+#include <Kernel/Storage/StorageController.h>
+#include <Kernel/Storage/StorageDevice.h>
+
+namespace Kernel {
+
+class AsyncBlockDeviceRequest;
+
+class RamdiskController final : public StorageController {
+    AK_MAKE_ETERNAL
+public:
+public:
+    static NonnullRefPtr<RamdiskController> initialize();
+    virtual ~RamdiskController() override;
+
+    virtual Type type() const override { return Type::Ramdisk; }
+    virtual RefPtr<StorageDevice> device(u32 index) const override;
+    virtual bool reset() override;
+    virtual bool shutdown() override;
+    virtual size_t devices_count() const override;
+    virtual void start_request(const StorageDevice&, AsyncBlockDeviceRequest&) override;
+    virtual void complete_current_request(AsyncDeviceRequest::RequestResult) override;
+
+private:
+    RamdiskController();
+
+    NonnullRefPtrVector<RamdiskDevice> m_devices;
+};
+}

Kernel/Storage/RamdiskDevice.cpp

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/Memory.h>
+#include <AK/StringView.h>
+#include <Kernel/FileSystem/FileDescription.h>
+#include <Kernel/Storage/RamdiskController.h>
+#include <Kernel/Storage/RamdiskDevice.h>
+
+namespace Kernel {
+
+NonnullRefPtr<RamdiskDevice> RamdiskDevice::create(const RamdiskController& controller, OwnPtr<Region>&& region, int major, int minor)
+{
+    return adopt(*new RamdiskDevice(controller, move(region), major, minor));
+}
+
+RamdiskDevice::RamdiskDevice(const RamdiskController& controller, OwnPtr<Region>&& region, int major, int minor)
+    : StorageDevice(controller, major, minor, 512, 0)
+    , m_region(move(region))
+{
+    klog() << "Ramdisk: Device #" << minor << " @ " << m_region->vaddr() << " length " << m_region->size();
+}
+
+RamdiskDevice::~RamdiskDevice()
+{
+}
+
+const char* RamdiskDevice::class_name() const
+{
+    return "RamdiskDevice";
+}
+
+size_t RamdiskDevice::max_addressable_block() const
+{
+    return m_region->size() / 512;
+}
+
+void RamdiskDevice::start_request(AsyncBlockDeviceRequest& request)
+{
+    LOCKER(m_lock);
+
+    u8* base = m_region->vaddr().as_ptr();
+    size_t size = m_region->size();
+    u8* offset = base + request.block_index() * 512;
+    size_t length = request.block_count() * 512;
+
+    if ((offset + length > base + size) || (offset + length < base)) {
+        request.complete(AsyncDeviceRequest::Failure);
+    } else {
+        bool success;
+
+        if (request.request_type() == AsyncBlockDeviceRequest::Read) {
+            success = request.buffer().write(offset, length);
+        } else {
+            success = request.buffer().read(offset, length);
+        }
+
+        request.complete(success ? AsyncDeviceRequest::Success : AsyncDeviceRequest::MemoryFault);
+    }
+}
+
+}

Kernel/Storage/RamdiskDevice.h

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <Kernel/Lock.h>
+#include <Kernel/Storage/StorageDevice.h>
+
+namespace Kernel {
+
+class RamdiskController;
+
+class RamdiskDevice final : public StorageDevice {
+    friend class RamdiskController;
+    AK_MAKE_ETERNAL
+public:
+    static NonnullRefPtr<RamdiskDevice> create(const RamdiskController&, OwnPtr<Region>&& region, int major, int minor);
+    RamdiskDevice(const RamdiskController&, OwnPtr<Region>&&, int major, int minor);
+    virtual ~RamdiskDevice() override;
+
+    // ^StorageDevice
+    virtual Type type() const override { return StorageDevice::Type::Ramdisk; }
+    virtual size_t max_addressable_block() const override;
+
+    // ^BlockDevice
+    virtual void start_request(AsyncBlockDeviceRequest&) override;
+
+    // ^DiskDevice
+    virtual const char* class_name() const override;
+
+    bool is_slave() const;
+
+    Lock m_lock { "RamdiskDevice" };
+
+    OwnPtr<Region> m_region;
+};
+
+}

Kernel/Storage/StorageController.h

@@ -46,6 +46,7 @@ class StorageController : public RefCounted<StorageController> {
     AK_MAKE_ETERNAL
 public:
     enum class Type : u8 {
+        Ramdisk,
         IDE,
         NVMe
     };

Kernel/Storage/StorageDevice.h

@@ -39,6 +39,7 @@ class StorageDevice : public BlockDevice {
     AK_MAKE_ETERNAL
 public:
     enum class Type : u8 {
+        Ramdisk,
         IDE,
         NVMe,
     };

Kernel/Storage/StorageManagement.cpp

@@ -32,6 +32,7 @@
 #include <Kernel/Storage/Partition/EBRPartitionTable.h>
 #include <Kernel/Storage/Partition/GUIDPartitionTable.h>
 #include <Kernel/Storage/Partition/MBRPartitionTable.h>
+#include <Kernel/Storage/RamdiskController.h>
 #include <Kernel/Storage/StorageManagement.h>
 
 namespace Kernel {
@@ -64,6 +65,7 @@ NonnullRefPtrVector<StorageController> StorageManagement::enumerate_controllers(
             controllers.append(IDEController::initialize(address, force_pio));
         }
     });
+    controllers.append(RamdiskController::initialize());
     return controllers;
 }